The game is very similar to this except it's impossible to do it all in 90 seconds here.
Rules are simple: starting person makes a scenario and starts a sentence with a letter. The next person starts another sentence with the next letter, the person after that does the same and so on. When we eventually reach the starting letter, the person who hit that letter creates a new scenario, picks a new letter, and it starts over.
Example: (starting letter = B, scenario = the office building's on fire) Person 1: "Bring me this month's financial reports." Person 2: "Can't you see the building's on fire?" Person 3: "Does it matter?" Person 4: "Everyone else is evacuating."
Ok now it starts Scenario = You're on the Titanic when it crashes into the iceberg; Starting letter = J
Seems so. Well then, on with the tour. On our left, a band of eastern lowland gorillas are enjoying a snack of bamboo shoots while basking on the plains. On our right, a group of poachers are polishing their rifles and drinking whiskey. Wait a minute...
*turns to the right and opens window* Hello dear poachers, I hate to spoil your day but you just got caught by a bunch of tourists. Although you're probably too drunk to even care.